微合金钢热变形组织与性能演变的CA模拟

建立了预测微合金钢热变形奥氏体动态再结晶组织与性能演变的元胞自动机模型.采用基于位错密度的动态再结晶理论,主要考虑动态再结晶的形核、晶粒长大,实现对动态再结晶过程晶粒形态、体积分数及晶粒尺寸的定量化表征及其演变过程的可视化描述,获得了位错密度及流变应力等参数.模拟得到的动态再结晶组织形貌及基于位错密度变化计算出的流变应力与实验结果吻合较好.     

有机化学合成法制备碳纳米管/聚苯胺复合材料

通过有机化学合成法使苯胺单体接枝到碳纳米管表面,然后再经化学原位聚合法制备碳纳米管/聚苯胺复合材料.用傅立叶变换红外光谱和扫描电子显微镜对复合材料的成分和形貌进行表征.用循环伏安法、恒流充放电和电化学阻抗等电化学测试手段来表征复合材料的电化学性能.研究结果表明,所制备的复合材料比容量可达到152F/g(有机电解液),显著高于同样条件下的纯聚苯胺、纯碳纳米管及由原位化学聚合法所制备碳纳米管/聚苯胺复合材料的电化学容量(65、25、80F/g),显示出良好的应用前景.     

Millipede forming-a new metal forming approach

Millipede Forming is a novel metal forming method that has been proposed and developed recently.It can be applied to overcome fundamental limitations in conventional roll forming,and,in addition,used for incremental forging and integrated into a strip casting or extrusion process for downstream thickness reduction. In this new method,there are two main principles:①the use of an optimal transitional surface or space linking of the incoming material to the outgoing product,and②implementation of a method to...     

Superconducting Electronics Research at CSIRO Australia ——20 Years after Discovery of HTS

CSIRO has had a long-term research effort in superconductivity, in particular, since the discovery of HTS which promised big prospects. Significant progress has been made in research and development of HTS electronic devices and systems for practical applications such as mineral and exploration as well as some niche applications in emerging science and technology areas. This article presents an overview of the CSIRO research activities in HTS supercon- ducting electronics since 1987, outlining the HTS junction and device technology as well as various application systems developed by the group.     

Numerical modeling of multiphase flow,heat transfer and titanium flow behavior in blast furnace hearth

Understanding the complex phenomena in BF hearth is essential to increase furnace productivity and to extend furnace campaign.We have developed several continuum-based mathematical/numerical models to simulate the multi-phase flow,heat transfer and chemical reactions in the BF hearth.These models have generated an improved insight on the mechanisms for liquid drainage efficiency,lining erosion and wall protection in BF hearth under operational conditions.The current paper gives an overview of these studi...     

THR EFFECT OF OXIDE LAYER FORMATION ON THE ADHESION OF CONDUCTIVE POLYMER COATING TO A MILDSTEEL

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基于单模光纤选模机制的单模输出6芯光纤激光器

为了实现多芯光纤激光器的单模输出,提出一种新的选模机制,即利用单模光纤进行选模。采用单模光纤和全反镜相结合作为选模器件,可以使6芯光纤激光器中同相位超模的耦合效率远远大于其他高阶超模,从而使高阶超模得到有效的抑制,实现高亮度的同相位超模单模输出。为了提高同相位超模的耦合效率,可以进一步优化单模光纤纤芯尺寸,同时调节单模光纤和6芯光纤之间的间隙距离。将同相位超模的耦合效率代入速率方程进行理论模拟,证明输出功率和耦合效率之间的必然联系,结果显示同相位超模输出功率随着耦合效率的增大而增大,得到单模输出的最大光-光转换效率为63.7%。     

Synthesis of Al_2O_3-SiC Composite and Its Effect on the Properties of Low-carbon MgO-C Refractories

Al2O3-SiC composite was synthesized with pyrophyllite and natural graphite as raw materials by carbothermal reduction reaction under argon atmosphere. The effect of synthesis temperature on phase composition and microstructure was investigated. Low-carbon MgO-C refractories were prepared by using the synthesized Al2O3-SiC composite as additive. The effect of its addition on the slag penetration and corrosion resistance as well as oxidation resistance of the refractories was investigated, and the slag resist...     

Optimization of pass schedule to improve the strip shape in hot strip rolling

In this study,the authors proposed a new algorism which can simultaneously meets the strip shape control criterion and the strip crown control criterion.Based on the new algorism,the pass schedule is optimized to maximize the allowable PC angle range.To calculate the objective value for optimization of pass schedule,a slab method has been integrated with the roll stack deformation to simulate the strip profile.     

3D model study of coal/coke combustion in a blast furnace effects of coal properties

A three-dimensional mathematical model of the combustion of pulverized coal and coke has been developed.The model is applied to the blowpipe-tuyere-raceway-coke bed region in an ironmaking blast furnace in one computational domain,which includes two parts:pulverized coal combustion model in the blowpipe-tuyere-raceway cavity and the coal/coke combustion model in the surrounding coke bed.The effects of coal properties are examined comprehensively,in terms of coal burnout and gas species distributions.The ...